US5271549A - Multiple-lead element soldering method using sheet solder - Google Patents

Multiple-lead element soldering method using sheet solder Download PDF

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Publication number
US5271549A
US5271549A US08/021,685 US2168593A US5271549A US 5271549 A US5271549 A US 5271549A US 2168593 A US2168593 A US 2168593A US 5271549 A US5271549 A US 5271549A
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band
wiring pattern
shaped sheet
solder
lead
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US08/021,685
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Toshio Tohyama
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Sony Corp
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Sony Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K1/00—Soldering, e.g. brazing, or unsoldering
    • B23K1/0008—Soldering, e.g. brazing, or unsoldering specially adapted for particular articles or work
    • B23K1/0016—Brazing of electronic components
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
    • H05K3/341—Surface mounted components
    • H05K3/3421—Leaded components
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/30—Assembling printed circuits with electric components, e.g. with resistor
    • H05K3/32—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits
    • H05K3/34—Assembling printed circuits with electric components, e.g. with resistor electrically connecting electric components or wires to printed circuits by soldering
    • H05K3/3457—Solder materials or compositions; Methods of application thereof
    • H05K3/3478—Applying solder preforms; Transferring prefabricated solder patterns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/36—Electric or electronic devices
    • B23K2101/40—Semiconductor devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2223/00—Details relating to semiconductor or other solid state devices covered by the group H01L23/00
    • H01L2223/544—Marks applied to semiconductor devices or parts
    • H01L2223/54473—Marks applied to semiconductor devices or parts for use after dicing
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2223/00—Details relating to semiconductor or other solid state devices covered by the group H01L23/00
    • H01L2223/544—Marks applied to semiconductor devices or parts
    • H01L2223/54473—Marks applied to semiconductor devices or parts for use after dicing
    • H01L2223/54486—Located on package parts, e.g. encapsulation, leads, package substrate
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/0001—Technical content checked by a classifier
    • H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
    • H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
    • H05K2201/10613—Details of electrical connections of non-printed components, e.g. special leads
    • H05K2201/10621—Components characterised by their electrical contacts
    • H05K2201/10689—Leaded Integrated Circuit [IC] package, e.g. dual-in-line [DIL]
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/01—Tools for processing; Objects used during processing
    • H05K2203/0195—Tool for a process not provided for in H05K3/00, e.g. tool for handling objects using suction, for deforming objects, for applying local pressure
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
    • H05K2203/04—Soldering or other types of metallurgic bonding
    • H05K2203/0405—Solder foil, tape or wire
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • This invention relates to a method for soldering a multiple-lead semiconductor element (LSI) having multiple leads such as a large-capacity memory controller, a DRAM, etc. on a wiring board.
  • LSI multiple-lead semiconductor element
  • a high-density semiconductor circuit (a large-scale integration: LSI) circuit having multiple lead terminals has been developed in order to satisfy a requirement for making a semiconductor circuit high density.
  • a wiring board having thereon a wiring pattern which is so designed that a wiring pattern interval and a land interval of the wiring pattern are set to fine pitch (0.5 mm) has been frequently used.
  • FIG. 1(A) is a schematic diagram showing a conventional soldering method of soldering a QFP type of semiconductor circuit (LSI) on a fine-pitch wiring pattern.
  • a reference numeral 1 represents a surface mount device (SMD) having multiple lead terminals 2 projected from the bottom surface thereof, and a reference numeral 3 represents a fine-pitch wiring pattern having plural land portions, which is formed on a print board.
  • SMD surface mount device
  • Each of the lead terminals 2 of the SMD 1 is so designed to have the width below 0.2 mm and the thickness below 100 ⁇ m, for example, and the dimensional precision of each lead terminal has an error of several %. Therefore, when an ordinary soldering method is conducted on such lead terminals 2 of the SMD 1, failure of soldering occurs due to lead float, defective soldering, etc. after the SMD 1 is actually mounted on the wiring board, so that yield of a semiconductor circuit is reduced and its reliability is lowered.
  • soldering method has been conventionally conducted on the SMD 1. That is, a soldering plating is beforehand conducted on the wiring pattern side, the SMD 1 is positioned on the wiring pattern 3 so that the lead terminals 2 are positionally coincident with the land portions of the wiring pattern 3, and then the lead terminals 2 are heated from their upper sides by a heat press thereby soldering the lead terminals 2 on the wiring pattern 3.
  • a soldering plating is beforehand conducted on the wiring pattern side
  • the SMD 1 is positioned on the wiring pattern 3 so that the lead terminals 2 are positionally coincident with the land portions of the wiring pattern 3, and then the lead terminals 2 are heated from their upper sides by a heat press thereby soldering the lead terminals 2 on the wiring pattern 3.
  • the soldering plating enables solder to be laminated merely in 30 ⁇ m thickness at maximum.
  • the soldering plating contains a large amount of tin, and thus its connection strength is low.
  • flux-cored cream solder is coated on predetermined portions (land portions) of the wiring pattern by a screen printing method or the like, and then the multiple lead terminals are heated under press by the heat press, thereby soldering the SMD 1 on the wiring pattern.
  • the cream solder 4 is coated on the land portions of the wiring pattern in semi-paste form as shown in FIG. 1(B).
  • the lead terminals 2 of the SMD 1 is mounted on the cream solder 4, and then pushed against the cream solder 4 while heated by the heat press (trowel), so that the lead terminals 2 are soldered onto the wiring pattern 3 through the cream solder 4.
  • the heat press is cooled, and then is drawn up, thereby completing the soldering process.
  • the soldering with sufficient strength can be conducted.
  • the surface shape of the cream solder becomes hemispherical as shown in FIG. 1(B), so that when the lead terminals 2 are pushed by the heat press, each lead terminal is applied with a force in a direction as indicated by an arrow which is laterally deviated from the center portion of the lead terminal.
  • An object of this invention is to provide a multiple-lead element soldering method in which sufficient amount of solder can be supplied for a soldering process to prevent lead float and defective soldering.
  • Another object of this invention is to provide a multiple-lead element soldering method in which the soldering process can be carried out in accordance with the kind of a multiple-lead element such as LSI to improve producibility.
  • Another object of this invention is to provide a multiple-lead element soldering method in which the multiple-lead element can be mounted on a wiring board with no positional deviation and thus the multiple-lead element can be accurately soldered to a desired position.
  • the multiple-lead element soldering method of this invention contains a step of beforehand mounting a band-shaped sheet solder at portions on which lead terminals of the multiple-lead element are to be soldered, and a step of heating the band-shaped sheet solder by a heat press method to perform a soldering process.
  • the band-shaped sheet solder is so designed as to be flat, so that the multiple-lead element is not positionally deviated when it is subjected to a heat press process.
  • the supply amount of the solder is adjusted by varying the thickness of the band-shaped sheet solder, so that the soldering process can be carried out with sufficient amount of solder.
  • FIG. 1(A) is a schematic diagram showing a conventional soldering method of soldering an SMD (LSI) serving as a multiple lead element on fine-pitch wiring pattern;
  • FIG. 1(B) is a side view showing the positional relationship between the land portions of the wiring pattern and the multiple lead terminals of the SMD in the conventional soldering method of FIG. 1(A);
  • FIG. 2 is a diagram showing a series of processes (A) to (D) for soldering a multiple lead element using a soldering method of this invention.
  • FIG. 3 is a schematic diagram showing the soldering of a multiple lead terminal device by a heat press method.
  • FIG. 2 is a diagram showing a series of processes (A) to (D) for soldering a multiple lead element using a soldering method of this invention, and the same elements as FIG. 1 are represented by the same reference numerals.
  • a reference numeral 10 represents a substrate, and a wiring pattern 3 having land portions to be soldered to the lead terminals of an SMD 1 are formed on the surface of the substrate 10.
  • flux is coated on portions of the wiring pattern 3 to be soldered (hereinafter referred to as "land portions"), and then a band-shaped sheet solder 11 is mounted (set) on the wiring pattern 3 as shown in FIG. 2 in such a manner as to be bridged over the land portions of the wiring pattern 3.
  • the band-shaped sheet solder 11 may be designed in 0.03 mm thickness, 1 mm width and 38 mm length (which is dependent on the number of lead terminals of the SMD 1) for the soldering of a rectangular SMD having lead terminals of 0.5 mm pitch, for example.
  • the band-shaped sheet solder 11 is mounted at each of lead terminal positions of the respective sides (four portions) of the SMD 1.
  • the SMD 1 is automatically fed by an automatic insertion machine in the same manner as the conventional method, and mounted on the predetermined positions of the wiring pattern through the band-shaped sheet solders 11.
  • a trowel 12 for heat press pushes each of the lead terminals 2, and is heated by a heater.
  • the band-shaped sheet solders 11 are melted, and the lead terminals 2 of the SMD 1 are completely soldered onto the land portions of the wiring pattern 3.
  • the heating operation of the trowel is stopped, and it is upwardly drawn at the time when the solder is solidified, thereby completing the soldering process.
  • the lead terminals and the land portions of the wiring patterns are soldered by melting the band-shaped sheet solder 11, and by setting the thickness of the sheet solder to such a value that surplus solder occurs, and a sufficient amount of solder can be supplied in correspondence to the pitch and number of the lead terminals.
  • the trowel 12 for heat press is provided at the lower surface thereof with an opening portion whose dimension is equal to the outer dimension of the SMD 1 as shown in FIG. 3, and also provided therein with a sucker for suctionally hold the fed SMD 1 at the lower surface of the trowel 12.
  • the print wiring board 10 is positioned on a XY table 13 through a position control of a console (not shown) on the basis of the mount position of the SMD 1, and then the band-shaped sheet solder 11 is mounted at a predetermined position.
  • the trowel 12 which is also provided with a temperature sensor 12A is descended while suctionally holding the SMD 1, then pushed against the band-shaped sheet solder 11 at the position which is matched with the wiring pattern position, and then heated by a heater to carry out the soldering. Thereafter, the heating is stopped, and the trowel 12 is ascended to hold a next SMD at the time when the solder is solidified.
  • a band-shaped sheet solder is mounted on the wiring pattern, and the lead terminals and the land portions of the wiring patterns are soldered through the band-shaped sheet solder. Therefore, even when the heat press method is used for the soldering, the lead float and the defective soldering can be prevented, and the positional deviation of the SMD can be also prevented.
  • the soldering can be carried out while matched with various kinds of LSIs and multiple lead elements, and thus the producibility can be improved.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Mechanical Engineering (AREA)
  • Electric Connection Of Electric Components To Printed Circuits (AREA)
  • Lead Frames For Integrated Circuits (AREA)

Abstract

A multiple-lead element soldering method of this invention contains a step of beforehand mounting a band-shaped sheet solder on a wiring board so as to be bridged over land portions of a wiring pattern on which lead terminals of the multiple-lead element are to be soldered, and a step of heating the band-shaped sheet solder by a heat press method to melt the band-shaped sheet solder, whereby the land portions of the wiring pattern and the lead terminals of the multiple-lead element are accurately soldered through the melted band-shaped sheet solder with sufficient amount of solder.

Description

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for soldering a multiple-lead semiconductor element (LSI) having multiple leads such as a large-capacity memory controller, a DRAM, etc. on a wiring board.
2. Description of Related Art
Recently, a high-density semiconductor circuit (a large-scale integration: LSI) circuit having multiple lead terminals has been developed in order to satisfy a requirement for making a semiconductor circuit high density. In addition, in order to miniaturize the LSI circuit as described above, a wiring board having thereon a wiring pattern which is so designed that a wiring pattern interval and a land interval of the wiring pattern are set to fine pitch (0.5 mm) has been frequently used.
FIG. 1(A) is a schematic diagram showing a conventional soldering method of soldering a QFP type of semiconductor circuit (LSI) on a fine-pitch wiring pattern. In FIG. 1(A), a reference numeral 1 represents a surface mount device (SMD) having multiple lead terminals 2 projected from the bottom surface thereof, and a reference numeral 3 represents a fine-pitch wiring pattern having plural land portions, which is formed on a print board.
Each of the lead terminals 2 of the SMD 1 is so designed to have the width below 0.2 mm and the thickness below 100 μm, for example, and the dimensional precision of each lead terminal has an error of several %. Therefore, when an ordinary soldering method is conducted on such lead terminals 2 of the SMD 1, failure of soldering occurs due to lead float, defective soldering, etc. after the SMD 1 is actually mounted on the wiring board, so that yield of a semiconductor circuit is reduced and its reliability is lowered.
In order to overcome the above disadvantage, the following soldering method has been conventionally conducted on the SMD 1. That is, a soldering plating is beforehand conducted on the wiring pattern side, the SMD 1 is positioned on the wiring pattern 3 so that the lead terminals 2 are positionally coincident with the land portions of the wiring pattern 3, and then the lead terminals 2 are heated from their upper sides by a heat press thereby soldering the lead terminals 2 on the wiring pattern 3. However, in this method, it is difficult to perform the connection between the lead terminals 2 and the land portions 3 with sufficient amount of solder because the soldering plating enables solder to be laminated merely in 30 μm thickness at maximum. In addition, the soldering plating contains a large amount of tin, and thus its connection strength is low.
In order to perform the soldering with large amount of solder by the heat press, flux-cored cream solder is coated on predetermined portions (land portions) of the wiring pattern by a screen printing method or the like, and then the multiple lead terminals are heated under press by the heat press, thereby soldering the SMD 1 on the wiring pattern. In this case, if sufficient amount of cream solder is fed, the cream solder 4 is coated on the land portions of the wiring pattern in semi-paste form as shown in FIG. 1(B). Thereafter, the lead terminals 2 of the SMD 1 is mounted on the cream solder 4, and then pushed against the cream solder 4 while heated by the heat press (trowel), so that the lead terminals 2 are soldered onto the wiring pattern 3 through the cream solder 4. Thereafter, the heat press is cooled, and then is drawn up, thereby completing the soldering process.
In the above method, if the amount of cream solder is sufficient, the soldering with sufficient strength can be conducted. However, the surface shape of the cream solder becomes hemispherical as shown in FIG. 1(B), so that when the lead terminals 2 are pushed by the heat press, each lead terminal is applied with a force in a direction as indicated by an arrow which is laterally deviated from the center portion of the lead terminal.
Since the dimensional precision of the lead terminals of the SMD 1 can not be set to a high value, there occurs a problem that when the SMD 1 is soldered on a wiring pattern of fine pitch, a soldering bridge frequently occurs due to irregularity of pitch interval of the wiring pattern.
SUMMARY OF THE INVENTION
An object of this invention is to provide a multiple-lead element soldering method in which sufficient amount of solder can be supplied for a soldering process to prevent lead float and defective soldering.
Another object of this invention is to provide a multiple-lead element soldering method in which the soldering process can be carried out in accordance with the kind of a multiple-lead element such as LSI to improve producibility.
Another object of this invention is to provide a multiple-lead element soldering method in which the multiple-lead element can be mounted on a wiring board with no positional deviation and thus the multiple-lead element can be accurately soldered to a desired position.
In order to attain the above objects, the multiple-lead element soldering method of this invention contains a step of beforehand mounting a band-shaped sheet solder at portions on which lead terminals of the multiple-lead element are to be soldered, and a step of heating the band-shaped sheet solder by a heat press method to perform a soldering process.
According to the multiple-lead element soldering method of this invention, the band-shaped sheet solder is so designed as to be flat, so that the multiple-lead element is not positionally deviated when it is subjected to a heat press process. In addition, the supply amount of the solder is adjusted by varying the thickness of the band-shaped sheet solder, so that the soldering process can be carried out with sufficient amount of solder.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1(A) is a schematic diagram showing a conventional soldering method of soldering an SMD (LSI) serving as a multiple lead element on fine-pitch wiring pattern;
FIG. 1(B) is a side view showing the positional relationship between the land portions of the wiring pattern and the multiple lead terminals of the SMD in the conventional soldering method of FIG. 1(A);
FIG. 2 is a diagram showing a series of processes (A) to (D) for soldering a multiple lead element using a soldering method of this invention; and
FIG. 3 is a schematic diagram showing the soldering of a multiple lead terminal device by a heat press method.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
A preferred embodiment according to this invention will be described with reference to the accompanying drawings.
FIG. 2 is a diagram showing a series of processes (A) to (D) for soldering a multiple lead element using a soldering method of this invention, and the same elements as FIG. 1 are represented by the same reference numerals.
In FIG. 2, a reference numeral 10 represents a substrate, and a wiring pattern 3 having land portions to be soldered to the lead terminals of an SMD 1 are formed on the surface of the substrate 10. First, at the step [A], flux is coated on portions of the wiring pattern 3 to be soldered (hereinafter referred to as "land portions"), and then a band-shaped sheet solder 11 is mounted (set) on the wiring pattern 3 as shown in FIG. 2 in such a manner as to be bridged over the land portions of the wiring pattern 3. The band-shaped sheet solder 11 may be designed in 0.03 mm thickness, 1 mm width and 38 mm length (which is dependent on the number of lead terminals of the SMD 1) for the soldering of a rectangular SMD having lead terminals of 0.5 mm pitch, for example. The band-shaped sheet solder 11 is mounted at each of lead terminal positions of the respective sides (four portions) of the SMD 1.
Next, at a step [B], the SMD 1 is automatically fed by an automatic insertion machine in the same manner as the conventional method, and mounted on the predetermined positions of the wiring pattern through the band-shaped sheet solders 11. At a step [C], a trowel 12 for heat press pushes each of the lead terminals 2, and is heated by a heater. The band-shaped sheet solders 11 are melted, and the lead terminals 2 of the SMD 1 are completely soldered onto the land portions of the wiring pattern 3. Thereafter, at a step (D), the heating operation of the trowel is stopped, and it is upwardly drawn at the time when the solder is solidified, thereby completing the soldering process.
The lead terminals and the land portions of the wiring patterns are soldered by melting the band-shaped sheet solder 11, and by setting the thickness of the sheet solder to such a value that surplus solder occurs, and a sufficient amount of solder can be supplied in correspondence to the pitch and number of the lead terminals.
As shown in FIG. 3, the trowel 12 for heat press is provided at the lower surface thereof with an opening portion whose dimension is equal to the outer dimension of the SMD 1 as shown in FIG. 3, and also provided therein with a sucker for suctionally hold the fed SMD 1 at the lower surface of the trowel 12.
On the other hand, the print wiring board 10 is positioned on a XY table 13 through a position control of a console (not shown) on the basis of the mount position of the SMD 1, and then the band-shaped sheet solder 11 is mounted at a predetermined position.
The trowel 12 which is also provided with a temperature sensor 12A is descended while suctionally holding the SMD 1, then pushed against the band-shaped sheet solder 11 at the position which is matched with the wiring pattern position, and then heated by a heater to carry out the soldering. Thereafter, the heating is stopped, and the trowel 12 is ascended to hold a next SMD at the time when the solder is solidified.
As described above, according to the multiple lead element soldering method of this invention, in place of the cream solder, a band-shaped sheet solder is mounted on the wiring pattern, and the lead terminals and the land portions of the wiring patterns are soldered through the band-shaped sheet solder. Therefore, even when the heat press method is used for the soldering, the lead float and the defective soldering can be prevented, and the positional deviation of the SMD can be also prevented.
In addition, by selecting the thickness of the sheet solder in accordance with each SMD, the soldering can be carried out while matched with various kinds of LSIs and multiple lead elements, and thus the producibility can be improved.

Claims (5)

What is claimed is:
1. A method for soldering a multiple-lead element having multiple lead terminals on a wiring board having a wiring pattern thereon, comprising the steps of:
mounting a band-shaped sheet solder on the wiring pattern so as to be bridged over land portions of the wiring pattern which are located at soldering positions of a multiple-lead element;
positioning the multiple-lead element on the band-shaped sheet solder such that the land portions of the wiring pattern are positionally coincident with the multiple lead terminals respectively; and
pushing the positioned multiple-lead element while heating the band-shaped sheet solder by a heating member to melt the band-shaped sheet solder, so that the land portions of the wiring pattern and the multiple lead terminals are soldered through the band-shaped sheet solder.
2. The method as claimed in claim 1, further comprising a step of coating flux on the land portions of the wiring pattern before mounting the band-shaped sheet solder on the wiring pattern.
3. The method as claimed in claim 1, further comprising a step of setting the thickness of the band-shaped sheet solder to such a value that surplus solder occurs in a soldering process.
4. The method as claimed in claim 1, wherein the heating member comprises a trowel which is provided at the lower surface thereof with an opening surface whose dimension is equal to the outer dimension of the multiple-lead element, and also provided therein with a sucker for suctionally holding the multiple-lead element.
5. The method as claimed in claim 4, wherein said trowel is further provided with a temperature sensor.
US08/021,685 1992-03-30 1993-02-24 Multiple-lead element soldering method using sheet solder Expired - Fee Related US5271549A (en)

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JP4-102545 1992-03-30
JP4102545A JPH05283587A (en) 1992-03-30 1992-03-30 Soldering method of multiple-lead element

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5358169A (en) * 1994-01-14 1994-10-25 Caddock Electronics, Inc. Method of soldering leads to electrical components
US6396128B1 (en) * 2000-04-17 2002-05-28 Mitsubishi Denki Kabushiki Kaisha Fixing structure and fixing method for semiconductor integrated circuit apparatus
CN111836479A (en) * 2020-07-08 2020-10-27 苏州浪潮智能科技有限公司 Pad processing device and pad maintenance method

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Publication number Priority date Publication date Assignee Title
US3574923A (en) * 1967-06-15 1971-04-13 Western Electric Co Compensating base for simultaneously bonding multiple leads
JPS6451694A (en) * 1987-08-22 1989-02-27 Nippon Almit Kk Cream solder printing method by using metal mask or metal screen
US5180097A (en) * 1989-10-03 1993-01-19 Mitsubishi Denki Kabushiki Kaisha Method of mounting an electronic part onto a printed circuit board

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Publication number Priority date Publication date Assignee Title
US3574923A (en) * 1967-06-15 1971-04-13 Western Electric Co Compensating base for simultaneously bonding multiple leads
JPS6451694A (en) * 1987-08-22 1989-02-27 Nippon Almit Kk Cream solder printing method by using metal mask or metal screen
US5180097A (en) * 1989-10-03 1993-01-19 Mitsubishi Denki Kabushiki Kaisha Method of mounting an electronic part onto a printed circuit board

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* Cited by examiner, † Cited by third party
Title
IBM Technical Disclosure Bulletin, "Contact Solder Reflow Frame", vol. 30, No. 3, Aug. 1987.
IBM Technical Disclosure Bulletin, Contact Solder Reflow Frame , vol. 30, No. 3, Aug. 1987. *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5358169A (en) * 1994-01-14 1994-10-25 Caddock Electronics, Inc. Method of soldering leads to electrical components
EP0663691A2 (en) * 1994-01-14 1995-07-19 Caddock Electronics, Inc. Method of soldering leads to electrical components
EP0663691A3 (en) * 1994-01-14 1996-05-29 Caddock Electronics Inc Method of soldering leads to electrical components.
US6396128B1 (en) * 2000-04-17 2002-05-28 Mitsubishi Denki Kabushiki Kaisha Fixing structure and fixing method for semiconductor integrated circuit apparatus
CN111836479A (en) * 2020-07-08 2020-10-27 苏州浪潮智能科技有限公司 Pad processing device and pad maintenance method

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